Price-controlled fuel pump



March 12, 1957 T. B. HARPER PRICE-CONTROLLED FUEL PUMP 2 Sheets-Sheet 1Filed June 18, 1954 INVENTOR. 7 0 by B.HC!/",O/"

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PRICE-CONTROLLED FUEL PUMP INVENTOR. To bgfiHar'pe Unite States PatentPRICE-CONTROLLED FUEL PUMP Toby B. Harper, Dolph, Ark.

Application June 18, 1954, Serial No. 437,815

Claims. (Cl. ZZZ-=46) This invention relates to a price-controlled fuelpump and has for its primary object the provision of a simple, compactand inexpensive control system for a fuel pump which can be preset toautomatically deliver a given amount of fuel in terms of the total priceof the fuel to be delivered.

In order to avoid the nuisance of waiting for change after purchasinggasoline, for example, the customer often asks for an amount of gascorresponding to what he wishes to pay or to the change he may pull outof his pocket. Most often, the customer will ask for an even amount,such as $2.00 worth of gas, or $3.00 or $4.00 worth, as the case may be.A major object of the invention is to provide a device which can bepreset by the pump operator to the desired price, and when the amount offuel corresponding to that price has been delivered, the pump willautomatically shut off.

Another object is to produce such a device which can be readily set bymeans of electric pushbuttons to the desired amount.

Another object is to provide such a device as an attachment to astandard pump with a minimum of alteration or connection to the existingpump.

The specific nature of the invention as well as other obiects andadvantages thereof will clearly appear from a description of a preferredembodiment as shown in the accompanying drawings, in which:

Fig. 1 is a schematic and circuit drawing of the metercontrolledswitching system of my invention;

Fig. 2 is a side elevation of a counter-actuating solenoid for operatingthe number of dials and associated mechanism of my invention; and

Fig. 3 is a front elevation of a typical gasoline pump showing themanner in which my invention is attached thereto.

Referring to Fig. 3, a typical gas pump 2 is provided with the usualmeter face 5 for registering the unit price of gasoline, the number ofgallons delivered and the total price of the gas delivered. Such pumps,as is Well known, are electrically driven and are usually controlled bya hand-operated lever near the nozzle. Some pumps in common use areequipped with automatic nozzles which shut off the pump flow when thetank is filled, by means of an electric solenoid operating on theshutoil mechanism of the pump. It will be apparent that electricalcontrol of the cutoff operation may be ac-- complished either by a relaywhich cuts off the entire electrical supply to the pump or by a solenoidof known type mounted on the end of the hose adjacent to the nozzle toproduce the same shut-off operation as is normally done by the hand ofthe pump operator. For the purpose of illustration only, I show thelatter type in Fig. 3 at 6, being mounted on the end of the fueldelivery hose 8, and provided with insulated circuit wires which may becoiled around the hose and in contact therewith, or otherwise securedthereto. When the circuit is closed to the solenoid or to the relay, thesupply of gas will be abruptly stopped.

As shown in Fig. 3, I provide a box or casing 12 which may be attachedto the pump on the same side, 4, as face 5, and which contains most ofthe components of of my invention. The front of this casing 12 showsthree number wheels 14 which may be made more or less like the priceindicators in face 5 of the pump, to indicate dollars and cents up to$9.99, which is all that is required for most purposes, although if theprice of gasoline continues to rise, it may be desirable to add a fourthnumber wheel for tens of dollars.

One direct attachment to the existing price indicator is necessary. Itis required to attach a toothed wheel 16 (Fig. 1) to the unit centswheel (that is, 0-9, the last price wheel on the right) which willrotate together with the unit cents wheel. The toothed wheel is providedwith teeth which open and close a switch 26 ten times for eachrevolution of the unit cents wheel, so that for every penny registeredon the price indicator 5, a circuit controlled by the toothed wheel canbe opened and closed once. Thus electrical pulses are provided for theoperation of my device.

The circuit controlled by the toothed wheel 16 is shown in Fig. l. Aseparate housing 18 is shown attached to pump 4 for toothed wheel 16.Shaft 19 of the toothed wheel extends into the pump 4 and is coupledinto unit cents wheel 7 in any suitable manner, depending on thephysical arrangement of the pump elements, either directly or throughsuitable gearing so that toothed wheel 16 is driven in the desiredrelationship with the unit cents wheel of the pump. A manually-operatedswitch 20 is also provided in housing 18 having two sets of contacts 200and 20b, for disconnecting the entire system so as to enable the pumpmeter to be reset to zero after each sale without eifecting theoperation of my device, which is automatically reset to zero at the endof each filling operation. Also, where the amount of gas to be bought isnot announced in advance, there is no need to use my device, and switch20 can then be left open.

Terminals 22 and 24 of my device are connected to any suitable source ofcurrent, e. g., volts A.-C., which supplies the power for operating thedevice. When the circuit is closed, current flows from terminal 22through switch contacts 20:: and switch 26 each time contact is made dueto the action of the teeth of wheel 16, which is shown as having tenteeth, therefore the circuit will be closed at 26 each time anotherpenny registers on the main meter 5. Each resulting current pulse passesdown wire 28, through closed contact 3622 along wire 32 to solenoid 34.

Solenoid 34, when energized, pulls in a magnetic plunger 36 as shown inFig. 2, which swings lever 38, pivoted at 40, and retracts pawl 42 onetooth back on toothed ratchet wheel 44. Adjustable stop means areprovided on pin 46 for limiting the travel of. the pawl at each strokeas required for proper operation, and tension means 48 can be readilyadjusted to any desired tension by setting spring 50 to the desiredpoint on lever arm 52. The pawl operation is thus regularly andcompletely adjustable.

Ratchet wheel 44 rotates freely on shaft 54, which may also serve as theshaft for two identical ratchet wheels 56 and 58 as shown in Fig. 1.

Attached to the ratchet wheel 44 for rotation therewith as a rotary uniton shaft 54 are a number wheel 60 bearing the numbers from 0-9, aneccentric cam 62 for actuating a switch 64 once for each tenth pulsereceived by solenoid 34, and a brake pulley wheel 66 for providingcontrolled friction between the rotary unit and its shaft.

Suitable steps 68 and 70 may be keyed to shaft 54 to ensure retention ofthe rotary unit in the proper position with respect to solenoid 34. AV-belt 72 is provided which is tensioned and anchored by spring 74 toprovide sufiicient friction for the rotary unit on shaft 54, to in-.sure that retraction of pawl 42 does not change the position of therotary unit, but forward motion of pawl 42 under the action of spring48, on cessation of the current pulse, is sufficient to overcome thelight friction provided by the brake and advance the ratchet one tooth.If desired, a stationary spring pawl can be provided to insure thatreverse motion of the ratchet Wheel cannot take place, but with thesystem shown this is not necessary.

To continue with the circuit for energizing solenoid 34, the remainingterminal of the solenoid is connected to line 76, which leads back tothe other terminal 24 of the external power source. 7

The numbers on the number wheel 69 are placed thereon in backwardrelation to the numbers on the corresponding unit cents wheel of thepump, so that each time a penny more is registered on the pump dial, apenny less is registered on dial 60. The reason for this will beexplained later.

Insulated cam 62 is so arranged that once each complete revolution ofdial 613, when the dial registration is passing through zero, the cam 62actuates switch 64 to close both of the two circuits controlled by thisswitch momentarily. Upper switch 64a therefore closes a circuitmomentarily from switch 26 controlled by toothed wheel 16, line 28, line80, switch 64a, line 82, line 34, normally closed switch 86b, line 88,to the second solenoid )0, and from the other terminal of this solenoidback through line 76 to input terminal 24 as previously described. Thusit will be seen that whenever the unit wheel has indicated its tenthpenny, it is reset to zero, while the next number wheel to the left,which indicates tens (or dimes) is notched up one number. Solenoid 90 isidentical with solenoid 34 and on registering its tenth dime, its cam 92actuates its swtich 94a in the same fashion to close a circuit extendingfrom previously closed switch 64a, Wire 82, wire 96, switch 940, wire98, normally closed switch 100a, wire 192, normally closed switch 104a,wire 106 to the dollar solenoid 108, and back from this solenoid to wire76 as before. Thus every tenth operation of solenoid 90 will reset itsunit wheel to zero and register another unit on the dollars wheel. Thetiming of the insulated earns 62 and 92 is, of course, so phased withrespect to the respective teeth of toothed wheel 16 that switches 26,64a, and 94a are all closed simultaneously so that a pulse from switch26 can be transmitted through the other two switches in series.

The solenoid mechanism associated with solenoid 108 is identical withthose of solenoids 34 and 99, but it will be noted that its associatedswitch 100a is dilferent in that it is normally closed instead of beingnormally open like the previously described switches. Thus, when thedollar indicator is reset to Zero, its insulated cam 110 at this momentopens switch 100a, and the cam face is arranged to have a sufficientlylong dwell so that while the dollar wheel is indicating zero dollars,switch 109a remains open. Since the operation of my device is completedwhen all three dials indicate zero, this insures that at the conclusionof operation, the solenoid circuit is open, and the dollar indicationcan go no further.

Whenever the dollar indicator first reads zero, the other two indicatorsare necessarily also zero, since they are so set, and switches 64b, Mb,and 149017 are all closed. A circuit is thus established through allthree of these switches in series, from terminal 22, through line 73,switch 641), line 112, switch 941), line 1114, switch 136b, line 316,through shut-off solenoid 6, line 120, manual switch 2%, and backthrough line 122 to input terminal 24. This causes the solenoid to beactuated and the gas pump to be shut oif. initially, of course, thedials of my device had been set to the desired amount, and while gas wasbeing delivered, the number wheels were being stepped backward from thedesired amount toward zero. Thus when Zero is reached, the desiredamount is new registered on the main price meter of the fuel pump anddue to the action of switches 64b, 94b, and 10% as described above, thepump is shut off, which is the desired result.

It will now be shown how the desired amount is initially registered onthe three dials of my device. For this purpose I provide threepushbuttons 124, 126, and 123, respectively associated with solenoids34, and 108. When pushbutton 124- is depressed, it opens switch 30b andcloses switch 300. This closes a circuit from input terminal 22, throughline 139, through switch 30a, line 32, solenoid 34, and back to line 76as before. This retracts the solenoid plunger and upon release of button124 the number wheel 60 is stepped back one number. When pushbutton 124is depressed a second time, number wheel 60 is stepped back anotherunit. It can readily be seen that pushbuttons 124 and 126 operate inexactly the same way, that is, whenever each one of them is depressedonce, the associated number wheel is stepped one unit. Thus, by pressingeach pushbutton a number of times corresponding to the price desired,the total price can be set up in advance. In practice, since an integralnumber of dollars worth of gasoline is usually required, it is almostalways necessary only to push plunger 128 a few times, since this isalmost always in the range of the amount desired. However, if an oddnumber of pennies worth of gasoline is also required, this can readilybe registered by manipulating the pushbutton the necessary number oftimes.

It will thus be seen that I have provided a simple device which can beinexpensively made out of a few standard units, such as standard stackswitches, and other common parts such as pawl and ratchet solenoidcontrol mechanisms, etc. Alternatively, the unit wheel for each solenoidmay be readily assembled from inexpensively made stampings or castings.The device is also simple and practically foolproof in operation, andcan readily be attached to any standard pump of the various types now incommon use.

Instead of the ratchet plunger operating to step the ratchet wheel onthe return stroke by spring action, it could obviously he stepped on theinitial stroke and merely reset by the spring. Likewise, the normallyopen circuits could be operated as normally closed circuits, and viceversa.

It will be apparent that the embodiments shown are only exemplary andthat various modifications can be made in construction and arrangementwithin the scope of my invention as defined in the appended claims.

I claim:

1. For use with a fuel pump having a price meter for indicatingcontinuously the total price of the fuel pumped, means for shutting offthe pump when the price reaches a predetermined amount, comprising: asecond price meter manually adjustable to said predetermined amount, andoperable backward toward zero setting as gas is pumped, and switch meansoperated when said second meter reaches zero setting to stop the flow ofgas from said pump, said second price meter comprising separate numberwheels rotatable to display the respective digits of the price, eachfixed to a ratchet wheel having ratchet teeth corresponding to thenumber of digits on each number wheel, a solenoid for each ratchetwheel, a pawl for each ratchet wheel actuated by each said solenoid tostep said ratchet wheel one step each time the solenoid is energized anddeenergized and thus step the price count by one digit, means actuatedby the fuel meter of the pump for completing one cycle of energizationand deenergization of the cents wheel of said second meter foreach centsworth of fuel pumped and a cam rotatable with each number wheel, aswitch for each wheel except the highest order, operable by its cam whenthe number wheel passes through a given number setting to control theenergization of the solenoid of the next higher order Wheel up to thelast one.

2. The invention according to claim 1, and a switch for the highestorder wheel arranged to deenergize all of the solenoids at the zerosetting of said highest order wheel.

3. The invention according to claim 2, and a manually operable switchfor each solenoid for individually stepping each solenoid to a desiredsetting.

4. In a fluid dispensing apparatus, a pump for producing flow of liquid,a cost meter connected to be driven by said flow to register the cost ofthe fluid dis pensed, a rotary element connected to said cost meter, apulsing circuit controlled by said rotary element to produce a fixednumber of pulses for each revolution of said rotary element, a secondcost meter comprising a plurality of number wheels rotatable to displaythe respective digits of the desired cost and arranged to count backwardfrom said desired cost as said first cost meter counts forward towardsaid desired cost, means for setting said second cost meter to a desiredcost reading, switch means operable by each number wheel as it 6 reacheszero setting, and a circuit controlled by the concurrent operation ofall said separate switch means to cut off the flow of fluid.

5. The invention according to claim 4, said means for setting the secondcost meter comprising an individual manually operable switch means foreach number wheel, a separate solenoid operated ratchet for each numberWheel, and circuit means for connecting a source of power to eachsolenoid through its switch means each time said switch means ismanually operated to step each number wheel one unit each time itsassociated switch means is manually operated, to thereby set each numberwheel to a desired digit.

References Cited in the file of this patent UNITED STATES PATENTS2,060,674 Hicks Nov. 10, 1936 2,228,820 Griflith et a1. Jan. 14, 19412,269,937 Hart Jan. 13, 1942 2,348,769 Waugh May 16, 1944 2,577,115Eickner Dec. 4, 1951

